Stéphane Poulin

Psychogenic or neurogenic origin of agrammatism and foreign accent syndrome in a bipolar patient: a case report

BackgroundForeign accent syndrome (FAS) is a rare speech disorder characterized by the appearance of a new accent, different from the speakers native language and perceived as foreign by the speaker and the listener. In most of the reported cases, FAS follows stroke but has also been found following traumatic brain injury, cerebral haemorrhage and multiple sclerosis. In very few cases, FAS was reported in patients presenting with psychiatric disorders but the link between this condition and FAS was confirmed in only one case.Case presentationIn this report, we present the case of FG, a bipolar patient presenting with language disorders characterized by a foreign accent and agrammatism, initially categorized as being of psychogenic origin. The patient had an extensive neuropsychological and language evaluation as well as brain imaging exams. In addition to FAS and agrammatism, FG also showed a working memory deficit and executive dysfunction. Moreover, these clinical signs were related to altered cerebral activity on an FDG-PET scan that showed diffuse hypometabolism in the frontal, parietal and temporal lobes bilaterally as well as a focal deficit in the area of the anterior left temporal lobe. When compared to the MRI, these deficits were related to asymmetric atrophy, which was retrospectively seen in the left temporal and frontal opercular/insular region without a focal lesion.DiscussionTo our knowledge, FG is the first case of FAS imaged with an 18F-FDG-PET scan. The nature and type of neuropsychological and linguistic deficits, supported by neuroimaging data, exclude a neurotoxic or neurodegenerative origin for this patients clinical manifestations. For similar reasons, a psychogenic etiology is also highly improbable.ConclusionTo account for the FAS and agrammatism in FG, various explanations have been ruled out. Because of the focal deficit seen on the brain imaging, involving the left insular and anterior temporal cortex, two brain regions frequently involved in aphasic syndrome but also in FAS, a cerebrovascular origin must be considered the best explanation to account for FGs language deficits.

Multicenter Validation of an MMSE-MoCA Conversion Table

Accumulating evidence points to the superiority of the MoCA over the MMSE as a cognitive screening tool. To facilitate the transition from the MMSE to the MoCA in clinical and research settings, authors have developed MMSE‐MoCA conversion tables. However, it is unknown whether a conversion table generated from Alzheimers disease (AD) patients would apply to patients with other dementia subtypes like vascular dementia or frontotemporal dementia. Furthermore, the reliability and accuracy of MMSE‐MoCA conversion tables has not been properly evaluated.

Verbal Irony Comprehension in Older Adults With Amnestic Mild Cognitive Impairment

OBJECTIVE The present study examined verbal irony comprehension in 31 aMCI and 33 healthy control (HC) subjects. Although nonliteral language impairments have been evidenced in individuals with amnestic mild cognitive impairment (aMCI) or Alzheimers disease (AD), verbal irony comprehension remained somewhat underinvestigated in these populations. METHOD A task measured the capacity to attribute Second-order mental state (i.e., theory of mind; ToM) as well as the ability to distinguish an ironic statement from a lie. Subjects were asked to identify, in a short story, whether the final assertion was a lie or an ironic joke. RESULTS Our results showed lower performance on a verbal irony comprehension task for aMCI individuals compared with those in the HC group. This pattern of results was related to Second-order ToM and executive functions. CONCLUSION These findings have implications for the conceptualization of aMCI, and foster investigation of social language comprehension in neurodegenerative diseases such as prodromal AD. Results are discussed in light of actual linguistic theories. The importance of evaluating the role of underlying cognitive processes in verbal irony comprehension is also emphasized.

Mental State Inferences Abilities Contribution to Verbal Irony Comprehension in Older Adults with Mild Cognitive Impairment

Objective. The present study examined mentalizing capacities as well as the relative implication of mentalizing in the comprehension of ironic and sincere assertions among 30 older adults with mild cognitive impairment (MCI) and 30 healthy control (HC) subjects. Method. Subjects were administered a task evaluating mentalizing by means of short stories. A verbal irony comprehension task, in which participants had to identify ironic or sincere statements within short stories, was also administered; the design of the task allowed uniform implication of mentalizing across the conditions. Results. Findings indicated that participants with MCI have second-order mentalizing difficulties compared to HC subjects. Moreover, MCI participants were impaired compared to the HC group in identifying ironic or sincere stories, both requiring mental inference capacities. Conclusion. This study suggests that, in individuals with MCI, difficulties in the comprehension of ironic and sincere assertions are closely related to second-order mentalizing deficits. These findings support previous data suggesting a strong relationship between irony comprehension and mentalizing.

Cognition and anatomy of adult Niemann–Pick disease type C: Insights for the Alzheimer field

ABSTRACT Niemann–Pick disease type C (NPC) is a rare lysosomal storage disorder causing an intracellular lipid trafficking defect and varying damage to the spleen, liver, and central nervous system. The adult form, representing approximately 20% of the cases, is associated with progressive cognitive decline. Intriguingly, brains of adult NPC patients exhibit neurofibrillary tangles, a characteristic hallmark of Alzheimer’s disease (AD). However, the cognitive, psychiatric, and neuropathological features of adult NPC and their relation to AD have yet to be explored. We systematically reviewed the literature on adult NPC with a particular focus on cognitive and neuroanatomical abnormalities. The careful study of cognition in adult NPC allows drawing critical insights in our understanding of the pathophysiology of AD as well as normal cognition.

Lexical decision with pseudohomophones and reading in the semantic variant of primary progressive aphasia: A double dissociation

The co-occurrence of semantic impairment and surface dyslexia in the semantic variant of primary progressive aphasia (svPPA) has often been taken as supporting evidence for the central role of semantics in visual word processing. According to connectionist models, semantic access is needed to accurately read irregular words. They also postulate that reliance on semantics is necessary to perform the lexical decision task under certain circumstances (for example, when the stimulus list comprises pseudohomophones). In the present study, we report two svPPA cases: M.F. who presented with surface dyslexia but performed accurately on the lexical decision task with pseudohomophones, and R.L. who showed no surface dyslexia but performed below the normal range on the lexical decision task with pseudohomophones. This double dissociation between reading and lexical decision with pseudohomophones is in line with the dual-route cascaded (DRC) model of reading. According to this model, impairments in visual word processing in svPPA are not necessarily associated with the semantic deficits characterizing this disease. Our findings also call into question the central role given to semantics in visual word processing within the connectionist account.

Clinical Impact of a Second FDG-PET in Atypical/Unclear Dementia Syndromes.

Diagnosis of atypical/unclear dementia is often difficult and this delays treatment initiation. Several authors have shown that beyond standard dementia workup, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) reduces the number of unclear diagnoses, leads to earlier treatment, and has a beneficial impact on families. However, it is not uncommon that the FDG-PET findings are equivocal in this setting. For those cases, a repeat FDG-PET may clarify the diagnosis and prevent treatment delay. We retrospectively assessed the clinical impact of a repeat FDG-PET in 59 patients with atypical/unclear dementia syndromes and inconclusive initial FDG-PET. Changes in primary diagnosis, diagnostic confidence, and management following the second FDG-PET were examined. Conducting a second FDG-PET reduced the number of unclear diagnoses from 80% to 34% , led to diagnostic change in 24% of cases, and treatment modification in 22% of patients. Overall, the clinical impact was higher when initial diagnostic confidence was low and the second FDG-PET repeated ≥12 months after the first one. In tertiary care memory clinic settings, when diagnostic incertitude persists despite extensive evaluation and an equivocal FDG-PET, repeating the FDG-PET 12 months later can greatly clarify the diagnosis and improve management.

Risk Factors, Neuroanatomical Correlates, and Outcome of Neuropsychiatric Symptoms in Alzheimer’s Disease

BACKGROUND An integrative model of neuropsychiatric symptoms (NPS) in Alzheimers disease (AD) is lacking. OBJECTIVE In this study, we investigated the risk factors, anatomy, biology, and outcomes of NPS in AD. METHODS 181 subjects were included from the Alzheimers Disease Neuroimaging Study (ADNI). NPS were assessed with the Neuropsychiatric Inventory Questionnaire at baseline and 6 months. NPI >3 was used as a threshold for NPS positivity. Three NPS courses were characterized: 1) minimal/absent (negative at 0 and 6 months, n = 77); 2) fluctuating (positive only at one time point, n = 53); 3) persistent (positive at both time points, n = 51). We examined the association between NPS course and family history of dementia, personal history of psychiatric disorders, cerebrospinal fluid biomarkers, atrophy patterns, as well as longitudinal cognitive and functional measures at 12 and 24 months (MMSE, CDR-SOB, FAQ). RESULTS AD subjects with absent, fluctuating, or persistent NPS had similar CSF amyloid-β and tau levels. AD subjects with minimal/absent NPS had less personal history of psychiatric disorders (35%) than those with fluctuating (57%; p = 0.015) or persistent NPS (47%, not significant). At 24 months, AD subjects with persistent NPS had worse cognitive (MMSE; p = 0.05) and functional (CDR-SOB; p = 0.016) outcomes. Dorsolateral prefrontal atrophy was seen in persistent NPS, but not in fluctuating NPS. CONCLUSIONS Our results suggest that individuals with personal history of psychiatric disorders might be more vulnerable to develop NPS throughout the course of AD. The worst cognitive and functional outcomes associated with NPS in AD underscores the importance of monitoring NPS early in the disease course.

Validation of the Dépistage Cognitif de Québec: A New Cognitive Screening Tool for Atypical Dementias

Objective This study aimed to validate and provide normative data for the Dépistage Cognitif de Québec (DCQ; www.dcqtest.org), a new cognitive screening tool for atypical dementias. Method The DCQ was developed by expert behavioral neurologists and clinical neuropsychologists based on updated criteria for Alzheimers disease, primary progressive aphasia, and behavioral variant frontotemporal dementia. It targets five relevant domains: Memory, Visuospatial, Executive, Language, and Behavior. Validation was performed in a population-based sample of 410 healthy French-speaking Canadians aged between 50 and 89 years old. Normative data were derived from a subsample of 285 participants. Results Mean DCQ total score (out of 100) was 89.17 (SD = 7.36). Pearsons correlation coefficient showed a strong and significant correlation (r = .71, p < .001) with the Montreal Cognitive Assessment. Internal consistency for the cognitive domains assessed by Cronbachs alpha was satisfactory (.74). Test-retest reliability was adequate (Pearsons coefficient = . 70, p < .001) and interrater reliability, excellent (intraclass correlation = .99, p < .001). Normative data shown in percentiles were stratified by age and education. Conclusions This study suggests that the DCQ is a valid and reliable cognitive screening test. Application of the DCQ on populations with atypical dementias is underway to derive sensitivity and specificity values for various dementias.

DÉ́PISTAGE COGNITIF DE QUÉBÉC (DCQ): VALIDATION AND NORMATIVE DATA FOR A NOVEL COGNITIVE SCREENING TOOL FOR ATYPICAL DEMENTIAS

Mental State Examination, the original version of the MoCA, and the quality of life scale CASP-19. A multiple regression analysis was performed to verify the influence of age and education and the predictive capacity of the original version of the test on its alternative version. Results: Cronbach’s alpha coefficient was .76. Elimination of any of the items of the 2 version of MoCA never reduces the reliability to below .73. Convergent validity was .65 (p<.001), and divergent validity was .03 (p1⁄40.79). Correlation between the 1 and the 2 version of MoCA was significant and high (r1⁄40.86). There was a negative effect of age (b 1⁄4–0.141, p < 0.01) and a positive effect of education (b 1⁄4–0.549, p < 0.001), but these two effects did not remained significant when the total score of the original form of MoCA was included in the regression model (b1⁄4–0.691, p < 0.001) (Figure1). Conclusions: Our preliminary results showed good psychometrical properties for the 2nd alternative form of the Spanish version and strong relations between forms. Further analyses are required in order to guarantee the use of the alternate Spanish version of the MoCA test in clinical follow-ups and longitudinal studies.